JPH11205545A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original reader with which image data exactly corresponding to the images of an original can be acquired without requiring much labor and time. SOLUTION: A longitudinal scale 2 for positioning is provided with two marks 9 and 9 for comparison so as to scan them through a scanner, the number of pulses for a motor required for scanning the original is acquired from the distance between the marks 9 and 9 for comparison and the number of pulses for the motor required for running the scanner between these marks 9 and 9 for comparison, and based on this number of pulses, the running of the scanner is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus which is used alone or incorporated in a copying machine, a facsimile or the like, and which scans a document to obtain image data.
More specifically, the present invention relates to a document reading apparatus capable of acquiring image data accurately corresponding to a document image without taking time and effort.

[0002]

2. Description of the Related Art Conventionally, a document reading apparatus that scans a document to obtain image data has been widely used. These conventional document reading apparatuses include a document placing table on which a document such as a contact glass is placed, and a scanner that scans the document placed on the document placing table to acquire image data. The scanner includes an exposure lamp for exposing a document on a document table in a main scanning direction, and a carriage on which the exposure lamp and the like are mounted. Then, while the original is scanned in the main scanning direction by the exposure lamp, the carriage is caused to travel in the sub-scanning direction by driving means including a motor and a driving force transmitting member for transmitting the driving force from the motor, thereby scanning the entire original. I do. The driving force transmission member includes a driving pulley to which driving force from the motor is transmitted, a timing belt or a wire bridged over the driving pulley, a driven pulley driven by the driving pulley via the timing belt or the wire, and the like. I have.

[0003]

In the conventional document reading apparatus as described above, even if the motor is driven at a constant frequency, the pitch size and pitch of the driving force transmitting members such as the driving pulley and the timing belt (wire) are determined. An error occurs in the travel of the scanner due to a processing error such as a circle diameter, and a difference occurs in a reading area and an image size between an image of a document and image data obtained by scanning.

As a technique for solving such a problem, Japanese Patent Laid-Open No. Hei 6-309480 discloses a mark sheet reading apparatus for reading a mark sheet, reads a standard mark sheet in advance, and obtains a shrinkage ratio generated when reading the mark sheet from the acquired data. Is described, and data of another mark sheet is corrected based on the contraction rate. However, in this technique, the work of placing the reference mark sheet on the reading table and reading it has to be performed, which takes time and effort. In addition, there is a possibility that precise correction cannot be performed because an error occurs when the reference mark sheet is placed on the reading table.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a document reading apparatus capable of acquiring image data accurately corresponding to a document image without taking time and effort. The purpose is to do.

[0006]

According to the first aspect of the present invention,
A document mounting table on which a document is placed, a scanner that travels along the document surface of the document placed on the document mounting table, scans the document, and acquires image data of the document, and runs the scanner. By driving means for driving and the scanner,
A calibration mark that can be scanned at a plurality of locations in the traveling direction of the scanner, and a scanner drive amount of the drive unit necessary for scanning the document is obtained from scanning of the calibration mark by the scanner, and the scanner drive amount The above object is achieved by providing control means for controlling travel of the scanner based on the scanning of the document.

According to a second aspect of the present invention, there is provided a document table on which a document is placed, and the document scans the document by traveling along a document surface of the document placed on the document table, and scans the image of the document. A scanner that acquires data, a driving unit that drives the scanner to travel, a calibration mark that can be scanned by the scanner at a plurality of locations in the traveling direction of the scanner, and a scan of the calibration mark by the scanner. The object is achieved by providing a correction unit that obtains an image data amount obtained by scanning a document and corrects the image data obtained by scanning the document based on the image data amount.

According to a third aspect of the present invention, in the first or second aspect of the present invention, there is provided a scale for positioning the original placed on the original placing table on the original placing table. The object is achieved by the calibration mark being attached to the scale.

According to a fourth aspect of the present invention, in the first or the second aspect of the present invention, the calibration mark is provided outside a document placing area of the document placing table to achieve the object. To achieve.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a schematic configuration diagram showing a first embodiment of a document reading apparatus of the present invention, and FIG. 2 is a schematic plan view of an apparatus main body of the document reading apparatus of the present embodiment.

As shown in FIGS. 1 and 2, the original reading apparatus according to the present embodiment has a contact glass 1 on a top surface of an apparatus main body 10, a condition designation key for acquiring operating conditions such as an original reading size, a numeric keypad, and the like. An operation unit (not shown) provided with a start button or the like for starting an operation is provided. A vertical scale 2 and a horizontal scale 8 are provided on the top surface of the apparatus main body 10 along two adjacent edges of the contact glass 1, and contact is made along these scales 2, 8. An original is placed on the glass 1.

As shown in FIG. 2, the vertical scale 2 is provided with calibration marks 9 at two locations on the lower surface of the vertical scale 2. The calibration marks 9, 9 can be imprinted or printed on the vertical scale 2, or can be provided with openings. In addition, this original reading device
As shown in FIG. 1, a motor 3 is provided inside the apparatus main body 10, and a drive pulley 4 is connected to a shaft of the motor 3. A timing belt 5 bridged between the driving pulley 4 and a driven pulley 7 of the driving pulley 4
, A carriage 6 is fixed, and the carriage 6 reciprocates in a direction parallel to the vertical scale 2 (the direction of the arrow A in the figure) by the rotation of the driving pulley 4.

The carriage 6 has an exposure lamp 11 for uniformly exposing the original on the contact glass 1 along the vertical scale 2 and a mirror (reflected light (image light)) from the original acquired by the exposure. When the motor 3 is driven, the exposure lamp 11 moves along the vertical scale 2 while exposing the original along the horizontal scale 8 to move the entire original. As the exposure is performed, image light is incident on a mirror (not shown). Then, the image light reflected by the mirror is incident on an image sensor (not shown) and is photoelectrically converted. Also, the calibration marks 9 attached to the horizontal scale are exposed by an exposure lamp similarly to the image of the document, incident on an image sensor (not shown), and photoelectrically converted.

The operations of the exposure lamp 11, the carriage 6, and other members are controlled by a control unit (not shown) in accordance with operating conditions and the like input from an operation unit. The control unit detects a difference between an actual arrangement of the calibration marks 9 and 9 and an arrangement on data acquired from scanning by the exposure lamp 11, and based on the difference,
The running of the carriage 6 on which the exposure lamp 11 is mounted during scanning of the document is controlled.

Next, the operation of the document reading apparatus of the present embodiment having the above-described configuration will be described. In the document reading apparatus according to the present embodiment, the document is placed on the contact glass 1 with the document reading surface facing the contact glass 1 and the long and short edges along the vertical scale 2 and the horizontal scale 8, respectively. Is done. When the start button of the operation unit is pressed, the control unit
And the number of pulses (pulses between marks) P1 of the drive motor required to move the carriage 6 between the two calibration marks 9 attached to the vertical scale 2.
To get.

The control unit may be configured to obtain an original based on the placed original, or obtain an input from the operation unit, to obtain an original required for reading the original, and to take into account an error in scanning the original. Travel distance of the carriage 6 (ideal travel distance)
Obtain L2. Then, the acquired number P of pulses between marks is obtained.
1 and the ideal travel distance L2 and the distance L1 between the actual calibration marks 9 and 9 stored in advance, the following equation 1
Thus, the number of pulses (required number of pulses) P2 required to cause the carriage 6 to travel the ideal traveling distance L2 in consideration of an error generated during document scanning is acquired.

[0017]

## EQU1 ## P2 = L2 / L1 × P1

Next, the control unit drives the motor based on the required travel distance L, exposes the original by the exposure lamp 11 while running the carriage 6 for the required number of pulses P2, and obtains image light. Acquire image data based on light.

As described above, in the document reading apparatus according to the present embodiment, before scanning the read document, the carriage is moved in advance to scan the calibration marks 9 attached to the vertical scale 2, thereby scanning the document. On the basis of the distance L1 between the calibration marks 9 and 9 and the required number of pulses P2 required for moving the carriage 6 at the distance L1, the carriage 6 travels the ideal travel distance L2 for practical use including a reading error. The required pulse number P2 is obtained. Therefore, according to the document reading apparatus of the present embodiment, the reference sheet or the like is not required, the labor and time for placing the reference sheet are not required, and the error that occurs when the reference sheet is placed is eliminated. The image data can be obtained by moving the carriage 6 within a range corresponding to the image of the above.

Next, a description will be given of a second embodiment of the document reading apparatus according to the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the same components and operations as those in the first embodiment is omitted. In the document reading apparatus according to the present embodiment, when the start button is pressed, the control unit detects the ideal traveling distance L obtained by detecting the carriage 6 on the basis of the placed document or acquiring the input from the operation unit.
The motor is driven with a pulse number (initial setting pulse number) P3 for a travel distance L3 that is longer than a predetermined distance than 2, and both the calibration marks 9 and 9 attached to the vertical scale 2 and the original are read. The number P1 of inter-mark pulses required for the distance between these two calibration marks 9 and 9 and the image data of the document are obtained at one time. Then, the control unit controls the required pulse number P in the same manner as in the first embodiment.
2 is obtained, and then the number of unnecessary pulses P ′ is obtained by the following equation (2).

[0021]

## EQU2 ## Unnecessary pulse number P '= initial set pulse number P3-necessary pulse number P2

Then, a portion of the image data corresponding to the unnecessary pulse number P 'is deleted from the obtained image data,
Only the remaining image data is used as image data corresponding to the document. Except for these points, the third embodiment is the same as the first embodiment.

In the document reading apparatus of this embodiment, the acquired image data is corrected without changing the number of pulses for moving the carriage 6. Therefore, according to the document reading apparatus of the present embodiment, the calibration marks 9
Is performed simultaneously with the reading of the image of the document, and the same effect as that of the first embodiment can be obtained more efficiently.

The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the gist of the present invention. For example, in each of the above-described embodiments, the calibration marks 9 and 9 are provided at two locations on the vertical scale 2, but the calibration marks are provided so as to be scannable at a plurality of locations in the traveling direction of the carriage. Often, it can be arranged on another member such as the contact glass 1. In particular, by attaching the calibration mark to the contact glass 1, the influence of the mounting error of the vertical scale 2, which occurs when the calibration mark is attached to the vertical scale 2, is avoided, and the carriage 6 moves more accurately. The distance can be corrected. Further, the calibration mark may be provided at three or more locations, or may be provided at only one location in a shape that is long in the traveling direction of the carriage. Note that it is preferable that the calibration mark be set so as to be readable at a distance as long as possible between the reading start position and the reading end position, in order to obtain the required travel distance L more precisely.

In the above embodiments, the range of the image area is corrected by partially deleting the image reading range and the image data obtained by reading the image. May be used to correct the image. The pulse number (pulse number between marks) P1 required for the carriage to travel the distance L1 between the calibration marks 9, 9 is
The information may not be acquired every time an image is read, and may be acquired only when the image reading apparatus is installed, or every predetermined number of operations, or every predetermined period.

[0026]

According to the first aspect of the present invention, the calibration mark is scanned by the scanner to acquire the travel amount of the scanner required for scanning the original, and the scanner is scanned based on the travel amount when scanning the original. Of the scanner, it is possible to correct the scanner's running error caused by the processing error of each member for calibrating the driving force transmitting means to the scanner, and to obtain image data exactly corresponding to the image of the original. Becomes
In addition, since calibration marks that can be scanned by the scanner are provided at a plurality of locations in the scanning direction of the scanner, there is no need for a calibration standard sheet or the like, and the time and effort required for placing the standard sheet on the document table. Do not need.

According to the second aspect of the present invention, the calibration mark is scanned by the scanner, the amount of image data to be acquired by scanning the original is acquired, and the original is scanned based on the amount of image data. Since the acquired image data is corrected, a driving error of the scanner caused by a processing error of each member for configuring and calibrating the driving force transmitting means to the scanner is corrected in the image data, and the image data accurately corresponding to the image of the document is corrected. Can be obtained. Further, since the correction is performed after acquiring the image data, the scanning of the calibration mark and the scanning of the image can be performed simultaneously, and efficiently,
Image data corresponding to the image of the document can be obtained. Furthermore, since calibration marks that can be scanned by the scanner are provided at a plurality of locations in the scanning direction of the scanner, there is no need for a standard sheet for calibration or the like, and the time and effort required for placing the standard sheet on the document table. Do not need.

According to the third aspect of the present invention, the difference between the actual position and the position on the data acquired by scanning is detected by the detecting means for the calibration mark attached to the scale. Alternatively, the effect of the invention described in claim 2 can be obtained.

According to the fourth aspect of the present invention, since the calibration mark is directly attached to the document table, the influence of the mounting error of the member with the calibration mark can be avoided, and the document can be more precisely placed. The amount of travel of the scanner required for scanning or the amount of image data to be acquired by scanning the original is acquired, and the effects of the first and second aspects of the present invention can be more favorably obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a document reading apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of the apparatus main body of the document reading apparatus according to the embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact glass (document mounting table) 2 Vertical scale 3 Motor 4 Drive pulley 5 Timing belt 6 Carriage (scanner) 7 Follower pulley 8 Horizontal scale 9 Calibration mark 10 Main body 11 Exposure lamp (scanner)

Claims (4)

[Claims] An original mounting table on which an original is mounted; a scanner which travels along an original surface of the original mounted on the original mounting table, scans the original, and acquires image data of the original; A driving unit for driving the scanner to travel, a calibration mark scannable by the scanner at a plurality of locations in the traveling direction of the scanner, and A document reading apparatus, comprising: a control unit that acquires a scanner driving amount of a driving unit, and controls running of the scanner during scanning of the document based on the scanner driving amount. 2. A document table on which a document is placed, and a scanner which travels along a document surface of the document placed on the document table, scans the document, and acquires image data of the document. A driving unit for driving the scanner to travel, a calibration mark scannable by the scanner at a plurality of locations in the traveling direction of the scanner, and a scanning of the document from the scanning of the calibration mark by the scanner. A document reading device, comprising: a correction unit configured to obtain an amount of image data to be read and correct the image data obtained by scanning the document based on the amount of image data. 3. A scale for positioning the original placed on the original placing table on the original placing table, wherein the calibration mark is provided on the scale. The document reading device according to claim 1. 4. The document reading apparatus according to claim 1, wherein the calibration mark is provided outside a document placing area of the document placing table.